Different from older SLR and DSLR systems, Four Thirds was designed from the base up to be totally digital. Many of the lenses have been significantly computerized, to a point that companies are providing firmware updates for a large number of them. Lens designs have been adapted to digital sensor requirements, most particularly through telecentric designing. The sensor size is somewhat less than a majority of DSLR cameras which implies that lenses, more than ever a telephoto lens, can be made quite a lot smaller. As an example, a Four Thirds System lens featuring a a focal length of 300mm could cover virtually the same viewing angle as a 600mm focal length lens as a 35 mm film lens, and is equally more compact. The Four Thirds System has a focal length multiplier (crop facto) of around 2.
May 15, 2011
Micro Four Thirds System
Micro Four Thirds model is in step with the telecentric
prerequisite for dedicated digital design (Having the
entrance pupil at infinity makes the lens object-space to be
telecentric). Light rays collide with the imaging element
virtually head-on for the most advantageous edge-to-edge
photo replica. It also allows a significantly greater
compact package than the original Four Thirds System (or any
other interchangeable lens system for that matter) as it
reduces the outside lens mount diameter by 6mm, plus cutting
the lens mount distance from the the image sensor (the
distance to the flange back) by virtually half.
May 15, 2011
Four Thirds Manufacturers'